1. Field of the Invention
The present disclosure relates to a motor of a vacuum cleaner, and more particularly, to a motor-noise absorbing apparatus of a vacuum cleaner capable of absorbing and reducing flow noise generating by air, which is discharged in a high speed from an impeller, in a discharge section from a guide vein to windows of a motor housing.
2. Description of the Related Art
Generally, a vacuum cleaner takes in air laden with foreign substance, such as dust or the like, and separates the foreign substance from the air. Such vacuum cleaners include a cleaner motor mounted therein to generate a suction force. Such a conventional cleaner motor is explained as follows with reference to FIG. 1.
As illustrated in FIG. 1, the conventional cleaner motor is provided with a cup-shaped motor housing 10. A front bearing 19a, which is fixed by a front cover 21, is installed on an opened front end of the motor housing 10. A rear bearing 19b is installed on the middle of a closed rear end of the motor housing 10. In addition, to supply electric power, a plurality of brushes 13 is symmetrically joined to both sides of the motor housing 10, and to discharge air taken into the motor housing 10, a plurality of windows are formed in a circumferential direction of the motor housing 10.
Also, a core 11 on which a coil 12 is wound is forcibly inserted into a bracket 14 and supported and fixed by the bracket 14 in the motor housing 10. A rotor 17 is inserted into and rotatably coupled to the stator core 11. In this case, a motor axis 18 is forcibly inserted into and fixed to a rotor 17 to move in combination therewith, and a commutator 15 with which the brushes 13 is fixed to come in close contact is forcibly inserted into and fixed to a rear side of the rotor 17. The motor axis 18 at both ends thereof is supported and fixed by the front and the rear bearing 19a and 19b. In addition, an impeller 23 is connected with one end of the motor axis 18 to move in combination with the motor axis 18 and thus to generate a suction force. A diffuser 25 is disposed in the vicinity of an outer circumferential surface of the impeller 23, and a guide vein 27 is integrally formed with a rear side of the diffuser 25. An impeller cover 29, which is joined with the opened front end of the motor housing 10 to accommodate the impeller 23, the diffuser 25 and the guide vein 27, is provided with an air inlet 29a at the middle thereof and forms an air discharging passage to discharge air taken in by a rotation of the impeller 23.
An operation of the cleaner motor constructed as described above is as follows. The rotor 17 is rotated by electrical interaction between a stator 11, 12 and the rotor 17 caused by applied electrical power. A rotating force of the rotor 17 is transmitted to the impeller 23 through the motor axis 18 supporting the rotor 17. After air is taken into the impeller cover 29 through the air inlet 29a thereof by the rotating force of the impeller 23, it is forced out in a high speed from the impeller 23 by an impeller vein formed in the impeller 23, which rotates in a high speed, and then flows into the guide vein 27 along a bent air passage formed by the impeller cover 29 via the diffuser 25 fixed in the vicinity of a peripheral part of the impeller 23. The air forced into the guide vein 27 flows out through a space S1 between the stator core 11 and the rotor 17 in the motor housing 10 and a space S2 between the motor housing 10 and the stator core 11. At this time, the air cools the stator core 11 and the rotor 17. The air is discharged outside the motor housing 10 through the plurality of windows of the motor housing 10 to produce a suction force required for the vacuum cleaner.
However, according to the cleaner motor as described above, a problem occurs, in that noise is generated as the air, the positive pressure of which is increased while passing through the impeller 23 and the diffuser 25 in turn by rotation movement of the impeller 23, flows out in a high speed through the spaces S1 and S2. Particularly, since the brushes 13 and the bracket 14 supporting the stator core 11 are complicatedly formed in the space S2, the air generates collision noise while colliding with the complicated structures as described above.
To address the problem, in Korean patent No. 474344 is disclosed a motor-noise absorbing apparatus in which a noise absorbing member formed of a metal net having certain meshes is inserted between a rear side of a housing cover and a front side of a protector to disturb the flow of air, which is discharged in a high speed toward a plurality of windows through the inside of a motor housing and, thus, to absorb and reduce flow noise.
However, since such a conventional motor-noise absorbing apparatus is made up of the metal net as described above, there is a limit to how far collision noise may be absorbed and reduced. This is because as described above, the collision noise is generated as most of the air moving toward the windows from the guide vein 27 passes through the space S2 between the motor housing 10 and the stator core 11 and thus collides with the complicated structures, such as the brushes 13 and the bracket 14. Thus, an amount of the collision noise, which can be absorbed and reduced by the conventional motor-noise absorbing apparatus, is restricted.